Method and device for acoustic sealing

Abstract

Acoustic reflective devices are provided. An acoustic reflective device is configured to be inserted into an orifice. The device includes a stressing device that can vary a volume in response to a voltage difference across a portion of the stressing device. The stressing device is at least partially surrounded by a membrane.

1. An acoustic reflective device comprising:
 a membrane; and 
 a stressing device, where the stressing device is operatively attached to the membrane, where the stressing device increases a stress in the membrane in response to an input, and where the increase in the stress changes an acoustic reflectivity of the membrane, 
 where the stressing device includes: 
 an electroactive polymer element; 
 a first electrode; and 
 a second electrode, where the first electrode contacts a first side of the electroactive polymer element, and the second electrode contacts a second side of the electroactive polymer element, where the input is an electric potential difference applied between the first and second electrodes, where when the electric potential difference is applied between the first and second electrodes a strain of the electroactive polymer element increases on the first side, where the first side is operatively attached to the membrane and as the strain increases on the first side the membrane is stressed. 
 
     
     
       2. The acoustic reflective device according to  claim 1  where the stressing device includes:
 an inflatable membrane, where the inflatable membrane is operatively attached to the membrane or the membrane is at least a portion of the inflatable membrane, and 
 a fluid in the inflatable membrane, where when the electric potential difference is input into the inflatable membrane the inflatable membrane undergoes a strain increase, and where as the strain increases the membrane is stressed. 
 
     
     
       3. An acoustic reflective device comprising:
 a membrane; and 
 a stressing device, where the stressing device is operatively attached to the membrane, where the stressing device increases a stress in the membrane in response to an input, and where the increase in the stress changes an acoustic reflectivity of the membrane, 
 where the input includes first and second inputs, where the stressing device includes: 
 a first electroactive polymer element; 
 a second electroactive polymer element; 
 a first electrode; 
 a second electrode, where the first electrode contacts a first side of the first electroactive polymer element, and the second electrode contacts a second side of the first electroactive polymer element, where the first input is a first electric potential difference applied between the first and second electrodes, where when the first electric potential difference is applied between the first and second electrodes a strain of the first electroactive polymer element increases on the first side of the first electroactive polymer element, where the first side of the first electroactive polymer element is operatively attached to the membrane; 
 a third electrode; and 
 a fourth electrode, where the third electrode contacts a first side of the second electroactive polymer element, and the fourth electrode contacts a second side of the second electroactive polymer element, where the second input is a second electric potential difference applied between the third and fourth electrodes, where when the second electric potential difference is applied between the third and fourth electrodes a strain of the second electroactive polymer element increases on the first side of the second electroactive polymer element, where the first side of the second electroactive polymer element is operatively attached to the membrane, where and as the strain increases on at least one of the first side of the first electroactive polymer element and the second electroactive polymer element the membrane is stressed. 
 
     
     
       4. The acoustic reflective device according to  claim 1 , where the electric potential difference is between about 0.5 and 15 volts. 
     
     
       5. The acoustic reflective device according to  claim 3 , where the first electric potential difference and the second electric potential difference are between about 0.5 and 15 volts. 
     
     
       6. The acoustic reflective device according to  claim 2 , where the fluid is at least one of a liquid and a gas. 
     
     
       7. The acoustic reflective device according to  claim 2 , where the fluid in the inflatable membrane results in an internal gauge pressure between about 0.5 bar and 1.5 bar. 
     
     
       8. The acoustic reflective device according to  claim 1  where the membrane is at least one of oval-shaped or conical shaped. 
     
     
       9. The acoustic reflective device according to  claim 1  where the acoustic reflective device is configured to stretch a wall of an ear canal via the membrane. 
     
     
       10. The acoustic reflective device according to  claim 1  where the acoustic reflective device is configured to reflect transmitted sound at an interface between a wall of an ear canal and the membrane via the acoustic reflectivity of the membrane.